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File uploading, file storage and CakePHPs MediaView class

This article includes how to upload and store files, because I've seen a lot of discussion about that too, but if you're just interested in how to use the MediaView class scroll down.

Handling file uploads in CakePHP

First let's start with the required form, to create a file upload form all you have to do is this:

echo $form->create('Media', array('action' => 'upload', 'type' => 'file'));
echo $form->file('file');
echo $form->submit(__('Upload', true));

 

The "type" in the options of Form::create() takes post, get or file. To configure the form for file uploading it has to be set to file which will render the form as a multipart/form-data form.

When you submit the form now, you'll get data like this in $this->data of your controller:

Array
(
	[Media] => Array
	(
		[file] => Array
		(
			[name] => cake.jpg
			[type] => image/jpeg
			[tmp_name] => /tmp/hp1083.tmp
			[error] => 0
			[size] => 24530
		)
	)
)

Ok, now the big question with a simple answer is where the file data should be processed, guess where. Right – in the model because it's data to deal with and validation to do against it. Because it's a recurring task to upload files I suggest you to write a behaviour for it or convert your existing component to a behaviour.

If you keep it generic you can extend it with a CsvUpload, VideoUpload or ImageUpload behaviour to process the file directly after its upload or do special stuff with it, like resizing the image or parsing the csv file and store its data in a (associated) model.

We're not going to show you our own code here for obvious reasons, but I'll give you a few hints what you can or should do inside of the behavior:

  1. Validate the uploaded field, the field itself contains already an error code if something was wrong with the upload. Here is a link to the php manual page that shows you the list of the errors that you can get from the form data. http://www.php.net/manual/en/features.file-upload.errors.php
  2. Validate the uploaded file, is it really the kind of file you want and does it really contain the data structure you want?
  3. Check if the target destination of the file is writeable, create directories, whatever is needed and error handling for it, I suggest you to use CakePHP's File and Folder classes for that.
  4. Add a callback like beforeFileSave() and afterFileSave() to allow possible extending behaviors to use them.

Database vs file system storage

Feel free to skip that part if you already store the files in the file system.

Storing files in the database is in nearly all cases a bad solution because when you get the file it has to go its way through the database connection, which can, specially on servers that are not in the same network, cause performance problems.

Advantages of storage in the file system:

  1. Easy and direct file access, to parse them (csv, xml...) or manipulate them (images)
  2. You don't need to install any additional software to manage them
  3. Easy to move and mount on other machines
  4. Smaller then stored in a DB

The suggested solution is to store meta data of the file like size, hash, maybe path and other related info in a DB table and save the file in the file system.

Some people come up with the security and want to store a file because of that in the database which is wrong. You should not store the file in a public accessible directory like the webroot of the application. Store it in another location like APP/media. You control the access to the file by checking the permissions against the DB records of your meta data and sending it by using the CakePHP MediaView class, I'll explain later how to use it.

I don't say that storage of files inside the DB is in general a bad idea but for web based applications it is in nearly every case a bad idea.

File system Performance

A bottleneck in the long run on every file system is a large amount of files in a single directory. Imagine just 10.000 users and each has an individual avatar image. Further ext3 for example is limited to 32000 sub folders, other file systems have maybe similar restrictions. You can find a list of file system limitations here: http://en.wikipedia.org/wiki/Comparison_of_file_systems#Limits

To avoid performance problems caused by that you should store your files in a pseudo-random directory structure like APP/media/32/a5/3n/. This will also allow you to easily mount some of the semi-random created directories on another machine in the case you run out of disk space.

/**
 * Builds a semi random path based on the id to avoid having thousands of files
 * or directories in one directory. This would result in a slowdown on most file systems.
 *
 * Works up to 5 level deep
 *
 * @see http://en.wikipedia.org/wiki/Comparison_of_file_systems#Limits
 * @param mixed $string
 * @param integer $level
 * @return mixed
 * @access protected
 */
	protected function _randomPath($string, $level = 3) {
		if (!$string) {
			throw new Exception(__('First argument is not a string!', true));
		}

		$string = crc32($string);
		$decrement = 0;
		$path = null;
		
		for ($i = 0; $i < $level; $i++) {
			$decrement = $decrement -2;
			$path .= sprintf("%02d" . DS, substr('000000' . $string, $decrement, 2));
		}

		return $path;
	}

You should also know that php running in safe mode does not allow you to create more then one directory deep in one call. You have to take this in consideration, the above function does not cover that because safe mode is basically deprecated and will be also removed in php6

Sending a file to the client – or the unknown MediaView class

From what I've seen in the ruins of outsourced projects that asked us for rescue and also in the CakePHP googlegroup I think not many people are aware that CakePHP has a view that is thought to be used for downloads and display (images, text...) of files. It's called the MediaView class.

I'll now explain you how to use this class to send files to the client.

/**
 * Sends a file to the client
 *
 * @param string $id UUID
 * @access public
 */
	public function download($id = null) {
		$this->Media->recursive = -1;
		$media = $this->Media->read(null, $id);

		if (empty($media)) {
		$this->redirect('/', 404, true);
		}
		
		$this->set('cache', '3 days');
		$this->set('download', true);
		$this->set('name', $media['Media']['slug']);
		$this->set('id', $media['Media']['filename']);
		$this->set('path', APP . 'media' . DS . $media['Media']['path']);
		$this->set('modified', $media['Media']['modified']);
		$this->set('mimeType', $media['Media']['mime_type']);
		$this->set('extension', $media['Media']['extension']);

		$this->view = 'Media';
		$this->autoLayout = false;
		if ($this->render() !== false) {
			$this->Media->updateAll(
				array('Media.downloads' => 'Media.downloads + 1'),
				array('Media.id' => $id));
		}
	}

You simply have to set autoLayout to false and the view class to media.

$this->view = 'Media';
$this->autoLayout = false;

There are a few view variables to set to “configure” the file download or display. To control if you want to make the client downloading the file or to display it, in the case of images for example, you simply set 'download' to true or false;

	$this->set('download', true);

You can control the browser caching of the file by setting cache. Please not that you do not have to use caching if download is set to true! Downloads do not need caching.

	$this->set('cache', '3 days');

The next part might be a little confusing, you have “id” and “name”. Id is the actual file on your server you want to send while name is the filename under which you want to send the file to the client. “path” is the path to the file on the server.

	$this->set('name', $media['Media']['slug']);
$this->set('id', $media['Media']['filename']);
$this->set('path', APP . 'media' . DS . $media['Media']['path']);

If you want to send a mime type that does not already in the MediaView class you can set it.

	$this->set('mimeType', $media['Media']['mime_type']);

If you don't set it, the class will try to determine the mime type by the extension.

	$this->set('extension', $media['Media']['extension']);

Note that you have to set the extension to make it work and that the extension is attached to the filename! If you store the filename with an extension you have to break it up.

When everything is set you can check if render() was successfully and do whatever you want after that, for example count the download.

	if ($this->render() !== false) {
	$this->Media->updateAll(
	array('Media.downloads' => 'Media.downloads + 1'),
	array('Media.id' => $id));
}

 

Closing words

I hope you enjoyed reading the article and it helped you improving your knowledge about CakePHP. Feel free to ask further questions by using the comment functionality. Have fun coding!

Latest articles

Window functions

This article is part of the CakeDC Advent Calendar 2025 (December 15th 2025) Did you ever wanted to provide a partial result as part of an existing report? Window functions were added in CakePHP 4.1 and provide a way to pull a rolling result expressed naturally using the ORM. We'll use CakePHP 5 code in this article. Apart from the examples described in the book https://book.cakephp.org/5/en/orm/query-builder.html#window-functions One common scenario where window functions are very useful are rolling results. Imagine we have a transactions table, where account transactions are stored including a dollar amount of the transaction. The following migration would describe an example transactions table class CreateTransactions extends \Migrations\BaseMigration { public function change(): void { $table = $this->table('transactions'); $table ->addColumn('occurred_on', 'date', [ 'null' => false, ]) ->addColumn('debit_account', 'string', [ 'limit' => 255, 'null' => false, ]) ->addColumn('credit_account', 'string', [ 'limit' => 255, 'null' => false, ]) ->addColumn('amount_cents', 'biginteger', [ 'null' => false, 'signed' => false, ]) ->addColumn('currency', 'string', [ 'limit' => 3, 'null' => false, 'default' => 'USD', ]) ->addColumn('reference', 'string', [ 'limit' => 255, 'null' => true, ]) ->addColumn('description', 'string', [ 'limit' => 255, 'null' => true, ]) ->addTimestamps('created', 'modified') ->addIndex(['occurred_on'], ['name' => 'idx_transactions_occurred_on']) ->addIndex(['debit_account'], ['name' => 'idx_transactions_debit_account']) ->addIndex(['credit_account'], ['name' => 'idx_transactions_credit_account']) ->addIndex(['reference'], ['name' => 'idx_transactions_reference']) ->create(); } } Now, let's imagine we want to build a report to render the transaction amounts, but we also want a rolling total. Using a window function, we could define a custom finder like this one: public function findWindowReport( SelectQuery $query, ?string $account, ?Date $from, ?Date $to ): SelectQuery { $q = $query ->select([ 'id', 'occurred_on', 'debit_account', 'credit_account', 'amount_cents', 'currency', 'reference', 'description', ]); // Optional filters if ($account) { $q->where(['debit_account' => $account]); } if ($from) { $q->where(['occurred_on >=' => $from]); } if ($to) { $q->where(['occurred_on <=' => $to]); } $runningWin = (new WindowExpression()) ->partition('debit_account') ->orderBy([ 'occurred_on' => 'ASC', 'id' => 'ASC' ]); $q->window('running_win', $runningWin); $q->select([ 'running_total_cents' => $q ->func()->sum('amount_cents') ->over('running_win'), ]); return $q->orderBy([ 'debit_account' => 'ASC', 'occurred_on' => 'ASC', 'id' => 'ASC' ]); } Note the WindowExpression defined will sum the amount for each debit_account to produce the running_total_cents. The result of the report, after formatting will look like this Occurred On Debit Account Credit Account Amount (USD) Running Total (USD) 1/3/25 assets:bank:checking income:services $2,095.75 $2,095.75 1/3/25 assets:bank:checking income:sales $2,241.42 $4,337.17 1/7/25 assets:bank:checking income:services $467.53 $4,804.70 1/10/25 assets:bank:checking income:subscriptions $2,973.41 $7,778.11 1/12/25 assets:bank:checking income:sales $2,747.07 $10,525.18 1/17/25 assets:bank:checking income:subscriptions $2,790.36 $13,315.54 1/21/25 assets:bank:checking income:subscriptions $1,891.35 $15,206.89 1/28/25 assets:bank:checking equity:owner $353.00 $15,559.89 Other typical applications of window functions are leaderboards (building paginated rankins with scores, sales, activities), analytics for cumulative metrics (like inventory evolution) and comparison between rows (to compute deltas) and de-duplication (to pick the most recent record for example). This is a very useful tool to provide a solution for these cases, fully integrated into the CakePHP ORM. This article is part of the CakeDC Advent Calendar 2025 (December 15th 2025)

CounterCacheBehavior in CakePHP

This article is part of the CakeDC Advent Calendar 2025 (December 2th 2025)

CounterCacheBehavior in CakePHP: what it is, when to use it, and what’s new in CakePHP 5.2

As your application grows, a very common pattern appears: you need to display things like “number of comments”, “number of tasks”, or “number of orders”, and you need to do it fast. Calculating these values with COUNT() queries can work until performance starts to suffer (and complexity increases because of filters, states, or joins). This is exactly where CounterCacheBehavior* becomes useful.

What is CounterCacheBehavior?

CounterCacheBehavior is a CakePHP ORM behavior that keeps a counter field in a “parent” table synchronized based on the records in a related table. Typical example:
  • Articles hasMany Comments
  • You want to store the number of comments in articles.comment_count
The behavior automatically increments, decrements, or recalculates that value when related records are created, deleted, or modified.

When should you use it?

Common use cases include:
  • Listings with counters (e.g. “Posts (123 comments)”).
  • Sorting by counters (most commented, most active, etc.).
  • Filtering by counters (categories with more than X products).
  • Avoiding repeated and expensive COUNT( ) queries.
The idea is simple: accept a small cost on writes in exchange for much faster reads.

Basic configuration

CounterCache is configured in the child table (the one that belongs to the parent). If Comments belongsTo Articles, the behavior lives in CommentsTable. // src/Model/Table/CommentsTable.php namespace App\Model\Table; use Cake\ORM\Table; class CommentsTable extends Table { public function initialize(array $config): void { parent::initialize($config); $this->belongsTo('Articles'); $this->addBehavior('CounterCache', [ 'Articles' => ['comment_count'] ]); } } Doing this, CakePHP will automatically keep articles.comment_count up to date.

CounterCache with conditions (scoped counters)

Often you don’t want to count everything, but only a subset: published comments, active records, non-spam items, etc. $this->addBehavior('CounterCache', [ 'Articles' => [ 'published_comment_count' => [ 'conditions' => ['Comments.is_published' => true] ] ] ]); This pattern is very useful for dashboards such as:
  • open issues.
  • completed tasks.
  • approved records.

CounterCache with callbacks (custom calculations)

In some cases, conditions are not enough and you need more complex logic (joins, dynamic filters, or advanced queries). CounterCacheBehavior allows you to define a callable to calculate the counter value. Important: when using callbacks, bulk updates with updateCounterCache() will not update counters defined with closures. This is an important limitation to keep in mind.

What’s new in CakePHP 5.2: rebuild counters from the console

Before CakePHP 5.2, rebuilding counters often meant writing your own scripts or commands, especially after:
  • bulk imports done directly in the database.
  • manual data fixes.
  • adding a new counter cache in production.
  • data becoming out of sync.
New command: bashbin/cake counter_cache CakePHP 5.2 introduced an official command to rebuild counter caches: bin/cake counter_cache --assoc Comments Articles This command recalculates all counters related to Comments in the Articles table. Processing large tables in batches For large datasets, you can rebuild counters in chunks: bin/cake counter_cache --assoc Comments --limit 100 --page 2 Articles When using --limit and --page, records are processed ordered by the table’s primary key. This command is ideal for maintenance tasks and for safely backfilling new counter caches without custom tooling.

What’s new in CakePHP 5.2: bulk updates from the ORM

In addition to the console command, CakePHP 5.2 added a new ORM method: CounterCacheBehavior::updateCounterCache() This allows you to update counters programmatically, in batches: // Update all configured counter caches in batches $this->Comments->updateCounterCache(); // Update only a specific association, 200 records per batch $this->Comments->updateCounterCache('Articles', 200); // Update only the first page $this->Comments->updateCounterCache('Articles', page: 1); This is available since CakePHP 5.2.0.

Complete practical example: Articles and Comments

Assume the following database structure:
  • articles: id, title, comment_count (int, default 0), published_comment_count (int, default 0).
  • comments: id, article_id, body, is_published.

1) Behavior configuration in CommentsTable:

$this->addBehavior('CounterCache', [ 'Articles' => [ 'comment_count', 'published_comment_count' => [ 'conditions' => ['Comments.is_published' => true] ] ] ]);

2) Populate existing data (production)

After deploying, rebuild counters: bin/cake counter_cache --assoc Comments Articles From that point on, counters will stay synchronized automatically.

Best practices and Common Mistakes

Here you have some best practices and common mistakes:
  • Add indexes to foreign keys (comments.article_id) and fields used in conditions (comments.is_published) for large datasets.
  • If you perform direct database imports (bypassing the ORM), remember to rebuild counters using bin/cake counter_cache or updateCounterCache().
  • Counters defined using closures are not updated by updateCounterCache().
  • If a record changes its foreign key (e.g. moving a comment from one article to another), CounterCache handles the increments and decrements safely.
This article is part of the CakeDC Advent Calendar 2025 (December 2th 2025)

The Generational Perception of Work and Productivity in the Remote-Work Era

Generational Work Illustration

The Generational Perception of Work and Productivity in the Remote-Work Era

In the year 2020, everything changed when the world stopped completely during COVID-19. The perception of safety, health, mental health, work, and private life completely turned around and led to a different conception of the world we knew. As the global pandemic thrived, we saw how many jobs could be done from home, because people had to reinvent themselves as we were not able to go to our workplaces. And it settled a statement, changing the perception of work dramatically. Before it, and for older generations, work was associated with physical presence, rigid schedules, and productivity measured by visible hours. But after it, younger generations saw the potential of working from home or being a so-called digital nomad, giving more priority to flexibility, emotional well-being, and measuring efficiency through results. This change reflects a social evolution guided by new technologies, new expectations, and a more connected workforce. Remote work has been key in this transformation. For thousands of professionals, the ability to work from home meant reclaiming personal time, reducing stress, and achieving a healthier work--life balance (for example, by reducing commuting time most people get almost 2 extra hours of personal time). Productivity did not decrease --- in many cases, it actually improved --- because the focus shifted from "time spent" to "goals achieved." This model has also shown that trust and autonomy can lead to more engaged teams. However, despite all of the perks, many companies are apparently eager to return to traditional workplaces. Maybe it is the fear of losing control or a lack of understanding of the new work dynamics, but this tendency threatens to undo meaningful progress for generations that have already experienced the freedom and effectiveness of remote work. Going back to the old-fashioned way of work feels like a step backward. So now, the challenge is to find a middle ground that acknowledges the cultural and technological changes of our time, passing the torch to a new generation of workers. Because productivity is no longer measured by how many people are sitting in a chair, but by the value of the final results. And if we want organizations truly prepared for the future, we must listen to younger generations and build work models that prioritize both results and workers' well-being. In CakeDC we do believe in remote work! Proving through the years that work can be done remotely no matter the timezone or language.

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